Adds a nested event_type attribute in the response
Adds a nested event_type attribute in the response

 - OperatorEvents now have a nested attribute 'event_type' in the
   response which are the serialized record for the OperatorEventType

FBRTMaka/ooi-ui-services,asascience-open/ooi-ui-services,birdage/ooi-ui-services,DanielJMaher/ooi-ui-services,Bobfrat/ooi-ui-services,oceanzus/ooi-ui-services